[cf. US Black conk pomade for the hair (Major); DAS conk (of Negroes) to apply a mixture containing lye to the hair in order to straighten it; hair treated in this way: a conk; cf. CONCH 2, perhaps from the straight hair of many Bahamian whites]
v. (of men) to have one's hair straightened: My daddy used to get his hair conk (Nassau). cf. IRON, PRESS (Nassau)